Posted
by
samzenpus
on Sunday September 05, 2010 @09:45AM
from the steep-and-clean dept.

cybernanga writes "A group of researchers in South Africa has developed a filter that can purify water straight from the bottle. The filter sits inside a tube fitted on top of a bottle and purifies water as it is poured on a cup. From the article: 'The designer behind the filter, Dr Eugene Cloete, from the Stellenbosch University in South Africa, says the filter is only as big as an ordinary tea bag. He says the product is cost-effective and easy to use. "We are coming in here at the fraction of the cost of anything else that is currently on the market," says Dr Cloete on BBC World Service.'"

I think you can buy them online for about $100 each. I bet you'd get a discount if you bought 1000.

If they can do 6000 liters of water then the price is probably competitive with teabags. I guess it depends on how people are organized and how they pay for them. Individuals won't have $100 to spend but governments and humanitarian programs will.

At 300 $ / can useful for 6000 liters isn't it better to drill a well?

Best method however would most likely be:a) kill their leaders.b) confiscate all weapons.c) give them 100% freedom and democracy.d) have them ban import of foreign food.e) give them generous (as in not greedy) small loans.

This clearly hasn't worked - read Amy Chua's "World on Fire" for an explanation of why. Better still, but probably too dense for the average reader is Barrington Moore's "Social Origins of Dictatorship and Democracy".

With those prices and 3rd world exchange rates, they'll never develop their economies! They'd be in perpetual debt for water bottles.

Even Britta costs a fraction of that, and, of course, chlorine bleach (as a pre-treatment to kill bacteria)is dirt cheap.

Meanwhile, a solar still can be made with a bucket, a plastic sheet, and some manual labor. Unlike a filter, it will continue to produce clean safe water year after year with no expendable. The construction technique is simple enough that adult supervised children can do it (and learn a science lesson in the process with an immediate application).

The developed world seems to have a bias against such solutions that don't make the 3rd world dependent on a continuous stream of "manna from heaven" in the form of manufactured goods. Part of that seems to be a bit of Marie Antoinette syndrome (just can't imagine a place where such cheap ubiquitous materials are expensive and rare). Part is that people imagine that accountant run businesses will lay off their drive for profit just a bit for the sake of humanitarian aid (they won't). Perhaps part because they might then start growing their own economy rather than becoming dirt cheap labor for our clothing industry.

Meanwhile, much of the problem will stop when the developed world kindly stops selling greedy warlords automatic weapons and all the ammo they can carry.

Woa, woa, woa...where do you get your prices? I LIVE 20 miles from the university. We are on a level here that you would not understand, so I won't try. We are wanting to SAVE LIVES . GEDDIT? Mainly rural South African lives. Mainly black South African lives. If you want to read about costs goto http://www.scidev.net/en/news/nano-tea-bag-purifies-water.html [scidev.net]. We are talking CENTS. So please talk SENSE. Yeesh....money, money, money. The South African tax payer is footing the bill OK??

Another cheap method for killing microbes is just to fill PET bottles (old coke bottles) with the water and leave them in the sun for a couple of days, of course the UV light breaks down not just the nasties but the bottle itself eventually.

The filter in the article is just an ordinary active carbon filter. This [ted.com] is waaay better.

Cool piece of equipment. It's basically an RO filter. The pressure required for operation comes from the user pumping it up with an air pump. It's also small enough to take camping or on long hikes if you have a source of untrusted water nearby.

Its just a bag of activated charcoal. Great at filtering out larger organics, not so good with microbial life forms and minerals.

I bought "cassette tape" sized bags of activated charcoal for my tropical fish tanks in the 80s. Glad to see the technology reinvented.

I'm not sure any amount of AC can protect fish from nearby rotenone spraying, then again its very hard to prove that without the AC bags my fish would not have died, its not like I was about to tempt fate. Thus plenty of opportunity for psuedo-s

A doctor that I knew back in the '70s did volunteer work for the World Health Organization, and spent a lot of time in some god-awful places. He told me that they would use Clorox bleach to purify their water. One cap full for a bucket of water. It tasted terrible, but as for the alternative for an industrial scale case of diarrhea . . . it was the lesser of two evils.

Actually, what they really need is the west to stop subsidizing farm production, thus depressing world market prices. They need the west to stop dumping free food into their economies, thus depressing local market prices. They need a level playing field where they can finally fucking compete. Maybe then they'll be able to invest in improved infrastructure and other necessities.

Government corruption is so rampant that pretty trying to organize pretty much anything on a large scale will fail. The only way to help is to get in there where the normal people live and solve their daily problems (water, food...). Things will only improve when they've got some free time left over after the daily subsistence tasks for other stuff. Free time equals education and building.

Government corruption is so rampant that pretty trying to organize pretty much anything on a large scale will fail.

Correct. Which is why you need a fair market in which communities and individuals can actually participate, such that wealth can be injected at the bottom of the socioeconomic ladder, rather than relying on handouts that are funneled through corrupt regimes.

Things will only improve when they've got some free time left over after the daily subsistence tasks for other stuff. Free time equals edu

Also are the west really "buying food for them" as much as "dumping food into their market for cheap because we got plenty to not risk a starvation, too bad they don't once the crop season goes bad in the western world"?

It's true that China have not invaded any parts of Africa. And I'm sure they never will, at least until they feel it's in their best interests to do so.

Coups-d'etat are more common than elections in Africa. When we see the president of Bongobongoland who signed a nice deal with the Chinese overthrown by someone who thinks he can sell the same stuff to someone else and stick the proceeds in an alpine bunker, then it'll get interesting [wikipedia.org]

P.S. I agree, Europe and the USA are equally bad and historically have be

The bleach will also break apart many kinds of contaminants, it won't remove heavy metals and whatnot, but I think bleach can break poisons.

Depends on the poison. Heavy metals like lead are unaffected by bleach as is arsenic. Both are known to be in groundwater whether naturally occurring or by pollution. It's often best to filter water before disinfecting it. Even then, bleach is only partially effective against common pathogens. From wikipedia:
"Neither chlorine (e.g., bleach) nor iodine alone is considered completely effective against Cryptosporidium, although they are partially effective against Giardia".

Be very careful with the clorox method. The clorox product line is quite different today and you probably do not want to use the versions with stain removers and other additives for water purification. From the clorox website:
"Disinfection of Drinking Water (Potable)... Only Clorox Regular-Bleach, of all the bleaches mentioned on this website, is approved for sanitization and disinfection...."

Also, does this approach work from bacteria to virus to cryptosporidium? My understanding is that the old s

Answering my own question:
"Results of the present study show for the first time that C. parvum oocysts exposed to undiluted laundry bleach for as long as 120 min are infectious for animals. Although bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that under practical conditions it is not an effective disinfectant for C. parvum oocysts."http://aem.asm.org/cgi/reprint/61/2/844.pdf [asm.org]

Also, does this approach work from bacteria to virus to cryptosporidium? My understanding is that the old school iodine tablets don't work on the later and that the military and NGOs have moved to chlorine dioxide based tablets. Much better tasting too. The caveat is that it takes something like 4 hours to kill the crypto compared to something like 15 to 30 minutes for the lesser "bugs".

There are basically two different types of treatment that work on two different types of microorganisms. Iodine and othe

The water treatment guys screwed up. Chlorinated water shouldn't taste awful after purification, certainly not even as bad as swimming pool water. The "art" of chlorination is to use just enough hypochlorite to oxidize all the microbial life, anything over and above that is wasting supplies, aim for the "faintest taste of chlorine". Also you can aerate the water, just pouring it from cup to cup for a few minutes will help noticeably. Storing treated water after Cl dissipates will allow whatever was grow

As someone who also lived in some god-aweful places, I'll tell you one cap for a bucket of water is going to burn your throat (unless it's a really big bucket). Usually you want no more than 8 drops of chlorine per gallon of water.

Well, it can go in *any* bottle, rather than needing a special bottle, meaning that you don't need to worry about losing your special bottle in areas where social stability is ephemeral at best. So a filter that can go in any old bottle you have laying around, and can be made cheaply, and is small, yes, is innovative. Sometimes it's not about function, it's about form.

I don't know about the "nano-fibers", though I've gotten to be suspicious of "nano" as a meaningless marketing term like "cyber" was ten years ago, but activated carbon's efficacy as a filter depends on how long it is kept in contact with the water, which is why those pricey tap filters are generally a waste of money. It's probably better than nothing if you're drinking water out of a stream or lake, but I'd be genuinely surprised if it was much better than nothing.

The inside of the tea bag material is coated with a thin film of biocides encapsulated within minute nanofibres, which kills all disease-causing microbes.
The bag is filled not with tea leaves but with active carbon granules that remove all harmful chemicals, for instance endocrine disruptors.
Each "tea bag" filter can clean one litre of the most polluted water to the point where it is 100% safe to drink.
Once used, the bag is thrown away, and a new one is i

Calling it a "tea bag" filter even though you don't use it like one (that is, place it in cup and let it sit for a while) is misleading. Should we call it a "USB thumb drive" water filter just because it's a similar size?

Not only is there the dubious claim that this will make water safe, and the implication that it is somehow different from other activated charcoal filters already made, but they stress how cheap or affordable it is, without ever giving any indication of a price. When someone tells you that something is inexpensive but doesn't want to tell you how much it will cost in any quantity, it will not be inexpensive.

I agree. I've seen many of the water purification straws which make a claim of making water safe but they never back it up with independent testing. These do have reams of association approvals and testimonials but no testing. I found and tried one that made claims of being tested by the military and that it had reams of testing done. I found that with great effort it worked for about two liters and then clogged and was useless. I didn't have to pay for it and didn't bother trying one again.

It's a filter with washable inlet filter, charcoal filter then a ceramic block. I've abused it and the brand name and product name are gone, sorry. I remember the process I used to find it but don't recall who I bought it from or what the brand name is.

You can google Individual Water Purifier mil spec and look for ones that are issued to troops. I was in error on having an NSN being enough and someone I know berated me for that.

You should request information from them such as "What military specifications d

That's close, I don't see any prefiltering but it has a ceramic filter which does all the work. I'd trust that if the British military uses it though I would want another filter for unclear water. I like the system farther down it can produce enough for a small group and the price is good. It would also need something to pre-filter unclear water unless I'm misreading it.

"Half the cost of anything else out there" is very nice, but doesn't tell us much. Wandering around the web, I find the lowest (retail) cost to be around $.50/gallon for single packaged filters. (Which will obviously be considerably lower in bulk and/or multi-packaged.)

Inexpensive filter straws have been around for years. I don't see how this is that much better. There was nothing in the article about price or effectiveness of the filter itself. All we have is the designer's opinion, and of course he's naturally going to praise his own invention.

I thought Teabaggers were all for restoring the rights given by the constitution

Wrong! Teabaggers are just another radical religeo/political movement that uses misinformation and outright lies to influence an ignorant public and gain members and momentum.

Recall the recent Beck rally on the steps of the Lincoln memorial. WARNING SIGN: Beck states "religion and christianity have returned to America" Same old christian coalition bullshit, different wrapper: "Separation of church and state is a luxury we can

Yes, the whole point of the TEA party is to give other people a group to demonize so that they won't turn on people in power. In two years when the presidency is up again there will be a ton of conservatives spouting TEA party lines to get elected. The people who really believe in minimalistic government and a return to the constitution won't be found in the media or any mainstream political party. Everyone in the "middle" just wants more control over us. When you vote democrat or republican all you're doin

Good post. You obviously read my disclaimer being you didn't flame me.Too bad politics and life today is nothing short of stupidity in action.I have little faith we will be able to free ourselves from the slime that encumbers us these days. Those in power keep the masses in ignorance and darkness. Very effective method of control..

not an USian here: if i am not mistaken Tea Party came to life as a result of grassroot efforts tied to the Ron Paul's presidential campaign of 2008 in rep party. Originally it was about returning to the strict constitutionalism - nothing more, nothing less.Now it becomes a sad caricature of its former self as Palins and Becks, seeing the growing discontent among masses and TP's numbers, decided to steal the momentum of the movement. They hijacked it for their own goals, twisting the founding principles.

Not quite, they are in favor of restoring the rights they like from the constitution, and then removing the first, 14th, and any other ammendments they don't like, and placing a wonderful totalitarian theocracy on top of it, rewriting our history, fucking all of the poor people until they live in tent cities or just flat out die, eliminating our education system and making church mandatory, and eliminating all non-christian thinking, as according to them it is a lie from the pit of hell.

i see a hole in your logic. How can there be a totalitarian state with a constitutionally limited government with majority of powers delegated to the states and with no public education brainwashing the masses? and how on earth the US survived the 19th century? There were no centralized education systems, no social security and no mandatory health insurance, no federal reserve micromanaging the economy.

How can the government brainwash a large number of people? They don't, Fox news does, and then takes over the government. To be fair they weren't the government when they brainwashed people by somehow convincing them that all of the false shit they say (literally, take notes for fox for 5 minutes, then fact check what they say. It is all bullshit pretty much, I do this when I want to get angry and pumped). Also, I believe public education ne

"I thought Teabaggers were all for restoring the rights given by the constitution, regardless as to whether what's being said doesn't agree with their worldview?"

That would conflict with being the same Religious Right who Karl Rove so brilliantly exploited in the past. Rove is mostly out of the current game, but it's being played by very capable (and rich) people.

Not sure what the Jehovah's Witness does for their worship or belief, with exception they are always there to knock on my door during dinner and hand me some crap declaring how much better the world is getting with each passing day.

Most Seventh Day Adventists however actually attend a traditional protestant church service. The difference is they observe the original "Seventh Day Sabbath" hence the name, as the Jewish faith does. There are NO s

Another advantage over boiling water that I can think of is that these filters cannot (easily) be used for anything else. If you need firewood/fuel to sterilize your water, you might face the choice of either the meat or the water being raw when you have limited fuel (or more likely porridge of some sort will take the fuel, since meat is a luxury). This filter makes the water pure, making the fuel available for other things by default.